Question

我正在使用此代码：

public class newtimer extends Activity {

    private Timer myTimer;

    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.main);

        myTimer = new Timer();
        myTimer.schedule(new TimerTask() {
            @Override
            public void run() {
                TimerMethod();
            }

        }, 0, 1000);
    }

    int number = 0;

    private void TimerMethod()
    {
        //This method is called directly by the timer
        //and runs in the same thread as the timer.

        //We call the method that will work with the UI
        //through the runOnUiThread method.

        Toast.makeText(this, "TimerMethod Running "+number, Toast.LENGTH_SHORT).show();

        this.runOnUiThread(Timer_Tick);
    }

    private Runnable Timer_Tick = new Runnable() {
        public void run() {

            //This method runs in the same thread as the UI.
            //Do something to the UI thread here

            Toast.makeText(getBaseContext(), "UI Thread Running "+number, Toast.LENGTH_SHORT).show();

        }
    };
}

当我运行它时，我在logcat中得到了这个异常：

09-06 21：39：39.701：ERROR / AndroidRuntime（1433）：java.lang.RuntimeException：无法在未调用Looper.prepare（）的线程内创建处理程序

Answer 1

我认为问题在于TimerMethod函数中的Toast.makeText(this, "TimerMethod Running "+number, Toast.LENGTH_SHORT).show(); - 您无法从工作线程调用与UI相关的任何函数。既然你已经在UI线程中运行的部分中有Toast，为什么在TimerMethod中有另一个Toast？

对于调试，我建议尽可能使用Log而不是Toast。

android计时器处理程序

1 个答案: